Boxcryptor

Boxcryptor is easy-to-use encryption software optimized for the cloud. It allows the secure use of cloud storage services without sacrificing privacy and comfort. Boxcryptor supports all major cloud storage providers (such as Dropbox, Google Drive, OneDrive, Box, SugarSync and many more) on all platforms (desktop and mobile). With Boxcryptor, your files go protected to your cloud provider and you can enjoy peace of mind knowing that your information cannot fall into the wrong hands.

With Boxcryptor, you can encrypt your files locally on your own device, before they are then synchronized to the cloud of your choice. To protect your files, Boxcryptor uses the AES-256 and RSA-4096 encryption algorithms.
Have your files with you, wherever you go.